The country's leading pediatricians group is pushing to have all children screened for autism twice by age two.
Pediatricians should also start looking for subtle signs that can occur as early as one year old, adds LaPook, even before a formal diagnosis:
There is no cure for the developmental disorder, but experts say that early therapy can lessen its severity.
The advice is meant to help both parents and doctors spot autism sooner. There is no cure for the disorder, but experts say that early therapy can lessen its severity.
"We think it's a very welcome turn of events," Marguerite Colston of the Autism Society of America told CBS News. "We welcome the pediatricians looking at this because the earlier autism can be identified the better chance we can get the children support and mainstream them."
Symptoms to watch for and the call for early screening come in two new reports. They are being released by the American Academy of Pediatrics on Monday at its annual meeting in San Francisco and will appear in the November issue of the journal Pediatrics and on the group's Web site.
Experts say one in 150 U.S. children have the troubling developmental disorder.
"Our goal is to have these children identified and diagnosed early so they can get services, so that when they're in second, third grade they're able to cope in a regular classroom," said Dr. Chris Johnson of the University of Texas Health Science Center in San Antonio. She co-authored the reports.
Helped early enough, Johnson told CBS News, autistic kids can go on to do well in mainstream schools.
The academy's renewed effort reflects growing awareness since its first autism guidelines in 2001. A 2006 policy statement urged autism screening for all children at their regular doctor visits at age 18 months and 24 months.
The authors caution that not all children who display a few of these symptoms are autistic and they said parents shouldn't overreact to quirky behavior.
Just because a child likes to line up toy cars or has temper tantrums "doesn't mean you need to have concern, if they're also interacting socially and also pretending with toys and communicating well," said co-author Dr. Scott Myers, a neurodevelopmental pediatrician in Danville, Pa.
"With awareness comes concern when there doesn't always need to be," he said. "These resources will help educate the reader as to which things you really need to be concerned about."
Another educational tool, a Web site that debuted in mid-October, offers dozens of video clips of autistic kids contrasted with unaffected children's behavior. That Web site - www.autismspeaks.org - is sponsored by two nonprofit advocacy groups: Autism Speaks and First Signs. They hope the site will promote early diagnosis and treatment to help children with autism lead more normal lives.
The two new reports say children with suspected autism should start treatment even before a formal diagnosis. They also warn parents about the special diets and alternative treatments endorsed by celebrities, saying there's no proof those work.
Recommended treatment should include at least 25 hours a week of intensive behavior-based therapy, including educational activities and speech therapy, according to the reports. They list several specific approaches that have been shown to help.
For very young children, therapy typically involves fun activities, such as bouncing balls back and forth or sharing toys to develop social skills; there is repeated praise for eye contact and other behavior autistic children often avoid.
Mary Grace Mauney, an 18-year-old high school senior from Lilburn, Ga., has a mild form of autism that wasn't diagnosed until she was 9.
As a young girl, she didn't smile, spoke in a very formal manner and began to repeat the last word or syllable of her sentences. She was prone to intense tantrums, but only outside school. There, she excelled and was in gifted classes.
"I took her to a therapist and they said she was just very sensitive and very intense and very creative," said her mother, Maureen, 54.
Pediatricians should send such children for "early intervention as soon as you even think there's a problem," Johnson said.
Dr. Ruby Roy, a pediatrician with Loyola University Medical Center, who treats at least 20 autistic children, applauded the reports.
"This is a disorder that is often missed, especially when it's mild, and the mild kids are the ones ... who can be helped the most," Roy said.
Dr. Dirk Steinert, who treats children and adults at Columbia St. Mary's clinic in suburban Milwaukee, said the push for early autism screening is important - but that it's tough to squeeze it into a child's regular wellness checkup.
Some pediatricians have tried scheduling a visit just to check for developmental problems, when children are 2½. The problem is that insurance doesn't always cover these extra visits, Steinert said.